#include <iostream>
using namespace std;

int multiply(int x, int y)
{
    if (y == 0)
        return 0;
    if (y%2 == 0)
        return 2*x*(y/2);
    else
        return x+2*x*(y/2);
}

void exam01(void)
{
    cout << multiply(11, 13) << endl;
}

